1. Field
Aspects of the present invention generally relate to a system where an image processing apparatus and an image output apparatus cooperate to perform image processing.
2. Description of the Related Art
In recent years, the protection of the natural environment has been increasingly attracting attention. Accordingly, electrical appliances need to be equipped with technology related to energy saving (power saving) in terms of protecting the natural environment. In a known power saving technique in an image processing system where an image processing apparatus and an image output apparatus cooperate to perform image processing, if the power switch of the image output apparatus is turned off, the image output apparatus and the image processing apparatus are both shut down (the publication of Japanese Patent Application Laid-Open No. 2004-262065).
Meanwhile, there is the Eco-Design Directive for Energy-related Products (hereinafter referred to as the “ErP Directive”) as a regulation for making environmentally conscious designs obligatory in energy-related products in European Union (EU) countries. This directive demands a reduction in the environmental load of an energy-using product in its entire life cycle. The ErP Directive includes Lot 26, which prescribes a standby state of a device having a network communication function. In terms of the environmental consciousness of energy, Lot 26 prescribes that the power supply of a device to be turned off when the device is not connected to a network.
In an image processing system as described above, print data created by a client computer provided on a public network is received by an image processing apparatus to which the print data is to be input. Then, the image processing apparatus performs raster image processing (RIP) on the print data, thereby generating image data. Then, the generated image data is transmitted to an image output apparatus, and the image output apparatus outputs the image data.
If, however, a communication abnormality occurs in the public network due to, for example, stoppage of a communication device, restart of a communication device, the disconnection of wiring, etc., the connection between the public network and the image processing apparatus is lost. Thus, to reduce the power consumption of the image processing apparatus when not connected to the network according to the regulation of the ErP Directive, the power supply of the image processing apparatus needs to be turned off. However, even if the power supply of the image processing apparatus has been turned off, an apparatus that cooperates with the image processing apparatus keeps operating with no purpose. This unnecessarily consumes power. This is not limited to an image processing system as described above, but is common to systems where a plurality of apparatuses cooperate to process a job received from a network.